/Engine/Source/Runtime/Engine/Classes/Components/SplineComponent.h
Specify the tangents at a given spline point
void SetTangentsAtSplinePoint ( int32 PointIndex, const FVector & InArriveTangent, const FVector & InLeaveTangent, [ESplineCoordinateSpace::Type](API\Runtime\Engine\Components\ESplineCoordinateSpace__Type) CoordinateSpace, bool bUpdateSpline )